Aerosols for therapeutic purposes are generated with aerosol generation devices. A fluid (i.e., medicament) to be nebulised is stored in an ampoule that can be inserted in the aerosol generation device. The inserted ampoule is opened with an opening element, such as a collar, cannula or hollow needle, provided in the aerosol generation device and the medicament stored in the ampoule is guided through the opening element into the device, where it is nebulised. A conventional aerosol generation device of this type is disclosed, for example, in US-A-2009/0293868.
The requirements placed on the aerosol generation device arise from the treatment to be performed with the aerosols. One of the requirements concerns dosage accuracy and precision, i.e., the accuracy and precision of the administered quantity of the medicament provided as an aerosol. Only if the dose of a medicament administered to a patient (user) is precisely established, a precise and effective treatment with highly effective medicaments can be carried out. One of the basic conditions influencing dosage accuracy and precision is the quantity of fluid to be nebulised that is guided from the ampoule into the aerosol generation device.
Known opening elements are made from materials having poor wetting characteristics, such as Grilamid resin or other materials, like plastic materials, with a higher contact angle or surface adhesion. The hydrophobicity or other features of these materials can impede the fluid released from the ampoule from draining through the opening element and into the aerosol generation device. The aerosol generation device cannot aerosolise the fluid from the ampoule unless the fluid comes into contact with an aerosol generating element of the device, such as a vibrating membrane with through holes. Any fluid that remains suspended in the opening element, rather than draining therethrough into the aerosol generation device, will not be aerosolised, thus leading to undesired variations in the emitted dose of a fluid (i.e., medicament). Such dosing variations can considerably compromise the effectiveness of the aerosol application (i.e., aerosol treatment).
A conventional opening element is disclosed, for example, in US-A-2009/0137950.